Flashcards on Statistical Analysis with R
Statistical Analysis with R: A Student's Guide to Models & Data
Tap to flip · Swipe to navigate
ANOVA
47 cards
Card 1
Question: What is the main biological question in this ANOVA experiment with cockroaches?
Answer: Whether the nutritional quality of the diet affects the size (weight) of the organisms.
Card 2
Question: What are the statistical hypotheses for this one-way ANOVA test?
Answer: H0: The weight is similar across diet groups. HA: The weight differs significantly across diet groups.
Card 3
Question: What is the predicted effect of a protein-enriched diet on weight?
Answer: It is expected that a protein-enriched diet will lead to the highest weight.
Card 4
Question: What categories (levels) does the DIET factor have in this experiment?
Answer: control, lipid1, lipid2, protein1, protein2.
Card 5
Question: How many observations were there for each diet group?
Answer: There were 17 observations for each diet group.
Card 6
Question: What is the statistical model used for analyzing weight?
Answer: weight_{ij} = DIET_j + ε_{ij}, where ε_{ij} ~ N(0, σ^2), independently for individual measurements.
Card 7
Question: What is the basic assumed property of the residuals ε_{ij} in this model?
Answer: The residuals are normally distributed with a mean of 0 and constant variance σ^2, and they are independent.
Card 8
Question: What is the dependent variable in this ANOVA experiment?
Answer: Weight in grams.
Card 9
Question: What is the purpose of using one-way ANOVA in this context?
Answer: To test whether the average weights differ among more than two groups (diets).
Card 10
Question: What does the equation toxin_{ijk} = α + SPECIES_j + DIAGNOSIS_k + SPECIES:DIAGNOSIS_{jk} + ε_{ijk} model in the context of ANOVA?
Answer: It models the main effects of species (SPECIES), diagnosis (DIAGNOSIS), and their interaction (SPECIES:DIAGNOSIS) on the toxin level, with residual no